�Լ�Һϸ��16S rRNAӫ�ⶨ��PCR������϶�ͯ��ŧ����Ĥ��

目的探讨儿童化脓性脑膜炎(化脑)新的快速诊断方法。方法2003-08—2005-12采用16SrRNA荧光定量法对浙江大学儿童医院49例临床疑似化脑患儿脑脊液(CSF)的细菌DNA进行测定;监测化脑患儿脑脊液细菌DNA拷贝数,同期进行CSF细菌培养的对照。结果(1)荧光定量PCR(FQ-PCR)检测49份脑脊液标本发现17份阳性,阳性率为34.7%(17/49),明显高于脑脊液培养的阳性率10.2%(5/49),差异具有显著性(P<0.01)。(2)对17份FQ-PCR阳性标本进一步测定细菌DNA的拷贝数,发现患儿病情与其DNA拷贝数呈正相关,与其Ct值(指每个反应管内的荧光信号到达设定的阈值时所经历的循环数)呈负相关,Ct值越低,脑脊液细菌DNA拷贝数越高,患儿的预后越差。(3)FQ-PCR、CSF细菌培养同时阳性的仅为5例。(4)对2例脑脊液FQ-PCR的产物测序,Ct值17.9的测序提示为大肠埃希菌,符合CSF细菌培养结果;Ct值31.8的,测序未果。结论荧光定量PCR特异性强、敏感性高,需标本量少,是早期快速诊断儿童化脑的可靠方法,具有较大的应用价值。     

Value of cerebrospinal fluid leukocyte aggregation in distinguishing the causes of meningitis in children

BACKGROUND: Current laboratory tests often cannot distinguish between bacterial and aseptic meningitis rapidly and accurately. The ability to make a prompt diagnosis has important implications for the management and outcome of children with meningitis. The observation that leukocytes aggregate in the cerebrospinal fluid (CSF) has been previously reported, and it has been advocated as a reliable method to distinguish the causes of meningitis in children. OBJECTIVE: To investigate the utility of CSF leukocyte aggregation as a screening test to distinguish between bacterial and aseptic meningitis. METHODS: We compared the clinical and laboratory indices of 109 prospectively enrolled patients with meningitis (67 bacterial, 23 viral, 19 undefined etiology) and evaluated the validity of the CSF leukocyte aggregation test. The predefined leukocyte aggregation scores (LAS) were compared among the types of meningitis, and correlations with other markers of inflammation were calculated. RESULTS: The median LAS was significantly higher (P < 0.001) in the bacterial (32.1%; range, 0 to 84.1%) than in the viral (0%; range, 0 to 16.6%) or undefined (0%; range, 0 to 20.7%) groups. The optimal sensitivity of the leukocyte aggregation test, 98.5 to 92.5%, was demonstrated with LAS values of 0 to 3%. The corresponding specificity was 64.3 to 88.1%. The peripheral white blood cell (WBC) count, serum C-reactive protein, CSF WBC count, blood culture, CSF Gram stain and CSF culture were inferior to the LAS as screening tests when compared individually. The LAS was as effective as CSF protein, TNF-alpha, IL-1-beta, IL-6 and IL-8 to predict bacterial meningitis. In a logistic regression model that included routine laboratory tests, the best predictor of bacterial meningitis was the LAS (odds ratio, 1.6 to 3.7). Significant correlations were demonstrated between the LAS and CSF protein, CSF WBC count, IL-1-beta, IL-6 and IL-8. Duration of symptoms before diagnosis, pretreatment with antibiotics, HIV-1 infection status and CSF red blood cell count did not significantly alter the LAS. CONCLUSIONS: There is no single test to diagnose the etiology of meningitis in children promptly and accurately. The finding of leukocyte aggregation in CSF might be of value as a sensitive adjunctive screening tool for the timely diagnosis of bacterial meningitis, recognizing that it has low specificity and potential practical limitations.     

Blood culture results as determinants in the organism identification of bacterial meningitis.

The diagnosis of bacterial meningitis depends on a lumbar puncture (LP). Sometimes, antibiotics are administered before a LP that is delayed owing to prior need for computerized tomography (CT) scan, technical problems, inability to obtain consent, or an unstable patient. We examined the accuracy of blood culture, cerebrospinal fluid (CSF) Gram's stain, and antigen detection by latex for organism identification of meningitis. All patients admitted to the Children's Hospital of Buffalo between January 1, 1984 and December 31, 1989 and having a CSF culture diagnosis of bacterial meningitis had their charts retrospectively reviewed. Patients excluded from the study were those with neural tube defects or CSF catheters, those admitted directly to the Intensive Care Nursery (ICN), those whose positive CSF cultures were determined to be a contaminant, those whose medical records were not found, or those older than 16 years. We analyzed a total of 178 patients with positive CSF cultures and the confirmed diagnosis of bacterial meningitis. Of 169 patients who had a blood culture performed, 86% had the organism responsible for meningitis recovered by this test, with the highest yield of 91% occurring in the 2.5-month to 24-month age group. Blood culture identified the bacteria in 94% of those patients with Haemophilus influenzae meningitis, and this yield increased to 100% when patients who had been pretreated with antibiotics were excluded. The combination of blood culture, CSF Gram's stain, and/or latex agglutination identified the causative bacteria in 92% of patients with meningitis. Blood culture, CSF Gram's stain, and latex agglutination are useful in identifying the organism causing pediatric meningitis.(ABSTRACT TRUNCATED AT 250 WORDS)     

新生儿细菌性脑膜炎预后不良的危险因素分析

目的 探讨新生儿细菌性脑膜炎预后不良的危险因素。方法 回顾性分析152例细菌性脑膜炎新生儿的临床资料,根据转归分为预后良好组（n=122）与预后不良组（n=30）,比较两组患儿的一般情况、首发症状及实验室检查结果,分析预后不良的危险因素。结果 预后不良组极低出生体重、外周血WBC < 5×10⁹/L或 > 20×10⁹/L、C-反应蛋白 > 50 mg/L、脑脊液WBC > 500×10⁶/L、脑脊液糖 < 1 mmol/L、脑脊液蛋白 > 2 g/L比例高于预后良好组（P < 0.05）,血培养和/或脑脊液培养阳性率、革兰阳性菌及无乳链球菌培养阳性率高于预后良好组（P < 0.05）。多因素logistic回归分析显示,脑脊液糖 < 1 mmol/L、脑脊液蛋白 > 2 g/L是新生儿细菌性脑膜炎预后不良的独立危险因素。结论 脑脊液糖 < 1 mmol/L、脑脊液蛋白 > 2 g/L是新生儿细菌性脑膜炎预后不良的危险因素。     

The Diagnostic and Predictive Value of Cerebrospinal Fluid Lactate in Children with Meningitis

ABSTRACT. One hundred and thirty-three children with suspected meningitis aged from 11 days to 16 years were investigated with routine cerebrospinal fluid (CSF) laboratory methods: microscopy of a Gram-stained smear, bacterial culture, determination of leukocytes, lactate, and the CSF/blood glucose ratio. On the basis of bacterial cultures and clinical course, the children were classified into three groups: bacterial meningitis (n=18), aseptic meningitis (n=28), and a control group (n=87). The main intention was to study the relation between current diagnostic methods and lactate. CSF lactate levels and cell counts, related significantly (p<0.01) better to the presence of bacterial meningitis than CSF/blood glucose ratios. Lactate levels exceed 2.4 mmol/l in all children with bacterial meningitis, but in none of the control group. Of 28 children with aseptic meningitis 3 had lactate in the range 2.5-2.7 mmol/l, while the others had values of 2.4 mmol/l or less. We consider CSF lactate to be the best predictor in the clinical decision to institute antibiotic treatment of children with suspected bacterial meningitis.     

C-reactive protein is useful in distinguishing Gram stain-negative bacterial meningitis from viral meningitis in children.

OBJECTIVE: To clarify to what extent Gram stain-negative bacterial meningitis can be distinguished from viral meningitis by assessment of cerebrospinal fluid (CSF) and blood indices and serum C-reactive protein (CRP) in children over 3 months of age. DESIGN: Common CSF indices, blood leukocyte counts, and serum CRP values were compared between patients with bacterial meningitis who had a positive CSF bacterial culture but a negative Gram stain and patients with viral meningitis. POPULATION: Three hundred twenty-five consecutive patients with CSF culture-proven bacterial meningitis, for whom Gram stain was negative in 55 cases, and 182 children with proven or presumed viral meningitis. RESULTS: Significant differences between patients with bacterial and viral meningitis were found in all indices with large overlap in all except serum CRP. In patients with bacterial meningitis, the mean CSF glucose concentration, protein concentration, leukocyte count, blood leukocyte count, and serum CRP were 2.9 mmol/L (52 mg/dL), 1.88 g/L, 4540 x 10(6)/L, 18.0 x 10(9)/L, and 115 mg/L; and in those with viral meningitis, mean values were 3.3 mmol/L (59 mg/dL), 0.52 g/L, 240 x 10(6)/L, 10.6 x 10(9)/L, and <20 mg/L, respectively. Of the tests investigated in this study, only serum CRP was capable of distinguishing Gram stain-negative bacterial meningitis from viral meningitis on admission with high sensitivity (96%), high specificity (93%), and high negative predictive value (99%). CONCLUSION: Exclusion of bacterial meningitis with only the conventional tests is difficult. Combined with careful physical examination and CSF analyses, serum CRP measurement affords substantial aid.     

High pneumococcal DNA loads are associated with mortality in Malawian children with invasive pneumococcal disease

BACKGROUND: In bacteremia owing to Streptococcus pneumoniae, high bacterial counts at presentation have been shown to be predictive of the development of serious invasive disease. Using real-time PCR, we aimed to determine pneumococcal DNA loads in blood and CSF, and their relationship to cytokine concentrations, clinical presentation and outcome. METHODS: Children with confirmed meningitis (n = 82) or pneumonia (n = 13) were prospectively recruited, and blood and CSF samples taken for pneumococcal bacterial DNA loads and cytokine determination. RESULTS: At the time of admission, the median bacterial load in blood was 1.6 x 10 DNA copies/mL (range 0.00-1.54 x 10) and in CSF it was 5.77 x 10 DNA copies/mL (range 4.42 x 10 to 6.15 x 10). Median blood and CSF bacterial loads (log DNA copies/mL) were significantly higher in nonsurvivors than in survivors; blood (3.80 vs. 2.97, P = 0.003), CSF (8.17 vs. 7.50, P = 0.03). In HIV-infected children (n = 59), blood and CSF loads and plasma tumor necrosis factor-alpha, interleukin-1beta (IL-1beta), IL-6 and IL-10 were all significantly higher in nonsurvivors than in survivors, but in HIV-uninfected children (n = 36) this difference was not significant. Blood bacterial loads and plasma cytokine concentrations were significantly associated, and were all significantly higher in children with meningitis than in those with pneumonia. In children with meningitis, median CSF cytokine concentrations were significantly higher than median plasma cytokine concentrations (P < 0.001) and CSF bacterial loads were significantly associated with CSF IL-1beta (P = 0.002) and IL-10 (P = 0.001) concentrations. CONCLUSIONS: Pneumococcal DNA loads are associated with plasma cytokine concentrations, and are higher in meningitis than in pneumonia. High blood and CSF pneumococcal DNA loads are associated with a fatal outcome.     

细菌16S rRNA基因实时荧光定量及分型方法的建立

目的：细菌培养、组织学、免疫学及普通PCR方法等在病原菌的检测方面都存在一定的不足,不能满足临床的需要,探索快速可靠的败血症和化脓性脑膜炎等细菌性感染疾病诊断的新方法是目前亟待解决的关键问题。方法：分析细菌16S rRNA 基因序列,在高度保守区自行设计通用引物和探针,以及革兰阳性和阴性分型探针,对12种标准菌株、23种临床培养分离株、乙型肝炎病毒、新型隐球菌及白色念珠菌、人基因组DNA等进行了荧光定量检测, 分析三种探针检测结果的相关性。结果：细菌16S rRNA基因荧光定量PCR具有较好的敏感性和特异性,最低能检测到10个拷贝的16S rRNA基因,即相当于2个细菌,与病毒、真菌及人基因组DNA等无交叉阳性反应;12种标准菌株、23种临床培养分离株均进行三种探针的荧光定量检测：通用探针均为阳性,18株革兰阳性菌株通过革兰阳性探针（G+Probe探针）检测为阳性,17株革兰阴性菌株通过革兰阴性探针（G-Probe探针）检测为阳性,反之均为阴性,吻合率100％。结论：建立了用通用引物和分型双荧光探针的细菌荧光定量PCR定量、分型方法。其检测方便,快速、敏感性和特异性高,符合率好,同时进行定量和分型,在病原菌检测方面具有推广及应用价值     

Relevance of common tests of cerebrospinal fluid in screening for bacterial meningitis

This study tests the hypothesis that if cerebrospinal fluid (CSF) has a nucleated blood cell count (NucBC) of less than 6/mm3, CSF tests other than bacterial culture need not be performed to exclude the diagnosis of bacterial meningitis in patients not receiving antimicrobial agents. The results of tests performed on the first specimen of CSF obtained for a given hospital visit from children younger than 3 years of age, exclusive of newborn infants admitted to the hospital on their date of birth, were analyzed. Of 3356 CSF specimens evaluated, 122 were from patients with bacterial meningitis; 460 specimens were analyzed separately because the erythrocyte count was greater than 1000/mm3. A negative CSF screening test result was defined as a CSF NucBC less than 6/mm3. In facilitating the diagnosis of bacterial meningitis, this screening test had a sensitivity of 98.4%, a specificity of 75.2%, and a negative predictive value of 99.9%. The other CSF tests varied widely in screening effectiveness: a Gram-stained smear had a sensitivity of 53% and a specificity of 97%. Receiver operating characteristic curve analysis was used to assess the screening relevance of CSF tests. The CSF NucBC and CSF segmented NucBC performed indistinguishably and superiorly compared with the CSF protein or glucose concentration and the ratio of CSF glucose to serum glucose concentration. Logistic regression analysis showed that the NucBC alone is superior to any combination of the other CSF tests. In a prospective study of 215 children younger than 3 years of age undergoing a lumbar puncture in our emergency department, 85% had empiric criteria identifying them as appropriate for an abbreviated CSF evaluation. The CSF NucBC was less than 6/mm3 in 70% of the 181 patients who would have been eligible for an abbreviated CSF evaluation. These data suggest that a strategy for the sequential testing of CSF could be adopted that would exclude unnecessary determinations and thereby save time, effort, and health care dollars.     

Cerebrospinal fluid C-reactive protein in the laboratory diagnosis of bacterial meningitis

Samples of cerebrospinal fluid from 112 cases of suspected meningitis were tested for the presence of C-reactive protein (CRP), using a qualitative and quantitative slide test. Bacterial meningitis was confirmed in 34 patients, based on CSF and blood culture results, and/or elevated CSF white blood cell (WBC) count and typical biochemical profile. There were 8 patients with early onset, and 3 who had received prior antimicrobial therapy among the 5 neonates, 23 children, and 6 adults with bacterial meningitis. Organisms recovered from CSF, and/or blood, included Haemophilus influenzae 14, Streptococcus pneumoniae 9, Streptococcus group B-5, Staphylococcus aureus 2, E. coli 2 and Klebsiella pneumoniae 1. Slide test was positive for CRP in 33 cases, giving a sensitivity of 97% which compared favourably with elevated CSF protein 33%, decreased CFS glucose 64.7% CSF glucose/blood glucose less than 1/2, 85%, raised CSF WBC 38.2%, raised CSF PMN 61.7%, CSF culture positive 88.2%, and CSF gram-positive 82.5%. Slide test was positive for CRP in 1 of 78 CSF samples negative for bacterial meningitis, giving a specificity of 98%. It was concluded that testing of CSF for CRP is a simple, rapid and accurate method for the laboratory diagnosis of bacterial meningitis, which is particularly appropriate for areas lacking adequate laboratory facilities.     

The diagnostic and predictive value of cerebrospinal fluid lactate in children with meningitis. Its relation to current diagnostic methods

One hundred and thirty-three children with suspected meningitis aged from 11 days to 16 years were investigated with routine cerebrospinal fluid (CSF) laboratory methods: microscopy of a Gram-stained smear, bacterial culture, determination of leukocytes, lactate, and the CSF/blood glucose ratio. On the basis of bacterial cultures and clinical course, the children were classified into three groups: bacterial meningitis (n = 18), aseptic meningitis (n = 28), and a control group (n = 87). The main intention was to study the relation between current diagnostic methods and lactate. CSF lactate levels and cell counts, related significantly (p less than 0.01) better to the presence of bacterial meningitis than CSF/blood glucose ratios. Lactate levels exceed 2.4 mmol/l in all children with bacterial meningitis, but in none of the control group. Of 28 children with aseptic meningitis 3 had lactate in the range 2.5-2.7 mmol/l, while the others had values of 2.4 mmol/l or less. We consider CSF lactate to be the best predictor in the clinical decision to institute antibiotic treatment of children with suspected bacterial meningitis.     

16S rRNA����оƬ�ӽ��������������������ŧ����Ĥ���ٴ��о�

目的 探讨新生儿化脓性脑膜炎(以下简称化脑)新的快速诊断方法.方法 2003年8至2006年2月浙江大学医学院附属儿童医院采用脑脊液细菌16S rRNA基因芯片技术对24例临床上疑似化脑患儿脑脊液(CSF)的细菌DNA进行测定,同期进行与CSF细菌培养的对照.结果 (1)49株细菌PCR扩增产物基因芯片杂交结果显示,33株C+菌其G+探针和通用探针均阳性,G-探针阴性;16株G-菌中,G-探针和通用探针均阳性,G+探针阴性,均能与相应特异的探针发生杂交.(2)大肠埃希菌DNA的PCR产物其16S rRNA基因芯片的最小检出量为1pg,约等于10个拷贝教,相当于2个细菌.(3)16S rRNA基因芯片检测24份脑脊液标本发现11份阳性,阳性率为45.83%(11/24),明显高于脑脊液培养的阳性率12.50%(3/24),差异有统计学意义(P<0.01).结论 脑脊液细菌16S rRNA基因芯片检测技术特异性强、敏感性高,需标本量少,是早期快速诊断儿童化脑的可靠方法,具有较大的应用价值.     

Cerebrospinal fluid concentrations of alpha-melanocyte-stimulating hormone in bacterial and aseptic meningitis

-Melanocyte-stimulating hormone (-MSH) has potent anti-inflammatory effects in several experimental models of inflammation. It inhibits both the actions and production of proinflammatory cytokines and neutrophil migration. We investigated whether -MSH in cerebrospinal fluid (CSF) increases during the acute stage in patients with bacterial and aseptic meningitis by measuring -MSH in CSF via radioimmunoassay. The -MSH concentrations in CSF from the children with bacterial meningitis who survived (n = 8), those with aseptic meningitis (n = 16), and the control subjects (n = 23) were all below the detection limit. However, CSF -MSH was elevated in four of the five children with bacterial meningitis who had neurological sequelae. We speculate that elevated -MSH levels in CSF during acute bacterial meningitis reflect negative feedback in response to severe inflammation associated with neurological sequelae induced by proinflammatory cytokines. Conclusion: CSF -MSH is elevated in children with severe bacterial meningitis who had neurological sequelae.     

A case of bacterial meningitis complicated by posttraumatic cerebrospinal fluid rhinorrhea

This paper reports an 11 year old boy with bacterial meningitis accompanied by post-traumatic cerebrospinal fluid (CSF) rhinorrhea. Streptococcus pneumoniae was cultured from CSF. The clinical course was very rapid before admission and his age relatively high for usual bacterial meningitis. Consequently, we examined the cause in detail. Immunological findings were within normal limits. Although routine graphic examinations, such as cranial X-ray photography, horizontal cranial computed tomography (CT) and magnetic resonance imaging, could not demonstrate a bone defect, both coronal thin-section cranial CT scanning and radioactive isotope counting by means of cotton packed into the nasal cavity were useful for detecting CSF rhinorrhea. In a case of atypical meningitis, the past history should be examined with caution and coronal thin-section CT should be performed.     

Predictors of bacterial meningitis in the era after Haemophilus influenzae.

OBJECTIVE: To determine if, in the era after Haemophilus influenzae type b, the cerebrospinal fluid (CSF) white blood cell (WBC) count can be safely used to stratify children suspected of having bacterial meningitis into low- and high-risk groups. DESIGN: Retrospective analysis of CSF samples. SETTING: Tertiary care pediatric center in Toronto, Ontario, between January 1, 1992, and October 1, 1996. PATIENTS: All CSF samples collected on children aged 2 months to 17 years were included. The final database consisted of 1617 atraumatic samples from children without prior neurologic or immunologic disease who underwent a lumbar puncture to assess the possibility of community-acquired bacterial meningitis. MAIN OUTCOME MEASURES: The predictive values of CSF WBC count, differential, protein, and glucose. RESULTS: There were 44 cases of bacterial meningitis. Five had 3 CSF WBCs per microliter or less, and 6 had 4 to 30 CSF WBCs per microliter. The negative predictive value of CSF specimens with 30 WBCs per microliter or less for bacterial meningitis was 99.3%. Cerebrospinal fluid samples with greater than 30 WBCs per microliter had a likelihood ratio for bacterial meningitis of 10.3 (95% confidence interval, 8.0-13.1) and a positive predictive value of 22.3%. Other significant predictors of bacterial meningitis included age, CSF glucose, protein, gram stain, CSF-serum glucose ratio, and peripheral blood band count. CONCLUSIONS: Given the occurrence of bacterial meningitis in children in the absence of CSF pleocytosis, other factors should be considered when managing children with suspected bacterial meningitis. Children older than 6 months with 30 CSF WBCs per microliter or less are at low risk for bacterial meningitis. If clinically stable and without other laboratory markers of bacterial meningitis, hospital admission and empiric antibiotic therapy may be unwarranted.     

Comparison of 16S rDNA-PCR Amplification and Culture of Cerebrospinal Fluid for Diagnosis of Bacterial Meningitis

Objective

Early and accurate diagnosis of bacterial meningitis is of critical concern. Optimum and rapid laboratory facilities are not routinely available for detecting the etiologic agents of meningitis. The objective of this study was to compare polymerase chain reaction (PCR) assay with culture for detection of bacteria in central nervous system (CNS) samples from patients suspected to have meningitis.

Methods

One-hundred cerebrospinal fluid (CSF) samples were obtained and divided into two parts. One part of samples was used for standard bacterial culture and gram staining. The remaining was used for DNA extraction. PCR assay was performed with universal primers for 16S rDNA gene of bacteria. Performance characteristics of the test were determined.

Findings

The PCR method was able to detect bacteria in all 36 culture-positive and in 38 of 64 culture-negative cases showing sensitivity and specificity of 100% and 40.6% respectively. Positive predictive value was 48.6% and negative predictive value 100%, however, Kappa coefficient showed the correlation of the 2 methods to be at 0.33.

Conclusion

There are advantages and disadvantages in performance characteristics of the conventional CSF culture and universal CSF 16S rDNA PCR. Therefore, it is recommended to use both methods in clinical practice, particularly in suspicious contaminated samples, with presumable presence of fastidious or slow growing bacteria because of antibiotic consumption.     

Test characteristics and interpretation of cerebrospinal fluid gram stain in children

BACKGROUND: Few data exist regarding the test characteristics of cerebrospinal fluid (CSF) Gram stain among children at risk for bacterial meningitis, especially the rate of false positive Gram stain. METHODS: We conducted a retrospective cohort study of children seen in the emergency department of Children's Hospital Boston who had CSF obtained between December 1992 and September 2005. Patients who had ventricular shunts, as well as those who received antibiotics before CSF was obtained were excluded. Test characteristics of CSF Gram stain were assessed using CSF culture as the criterion standard. Patients were considered to have bacterial meningitis if there was either: (1) growth of a pathogen, or (2) growth of a possible pathogen noted on the final CSF culture report and the patient was treated with a course of parenteral antibiotics for 7 days or more without other indication. RESULTS: A total of 17,569 eligible CSF specimens were collected among 16,036 patients during the 13-year study period. The median age of study subjects was 74 days. Seventy CSF specimens (0.4%) had organisms detected on Gram stain. The overall sensitivity of Gram stain to detect bacterial meningitis was 67% [42 of 63; 95% confidence interval (CI): 54-78] with a positive predictive value of 60% (42 of 70; 95% CI: 48-71). Most patients without bacterial meningitis have negative Gram stain [specificity 99.9% (17,478 of 17,506; 95% CI: 99.8-99.9)] with a negative predictive value of 99.9 (17,478 of 17,499; 95% CI: 99.8-99.9). CONCLUSIONS: CSF Gram stain is appropriately used by physicians in risk stratification for the diagnosis and empiric treatment of bacterial meningitis in children. Although a positive Gram stain result greatly increases the likelihood of bacterial meningitis; the result may be because of contamination or misinterpretation in 40% of cases and should not, by itself, result in a full treatment course for bacterial meningitis.     

Cerebrospinal fluid enrichment broth cultures rarely contribute to the diagnosis of bacterial meningitis

This study included children undergoing lumbar puncture in the emergency department. Bacteria were isolated from 34 (1.7%) of 1898 cerebrospinal fluid (CSF) enrichment broth cultures; 30 were contaminants. The primary CSF Gram stain was negative in all specimens with a positive enrichment broth culture. Enrichment broth cultures rarely contributed to the diagnosis of bacterial meningitis, and positive CSF enrichment broth cultures contributed to diagnostic uncertainty.     

Lipopolysaccharide binding protein is a potential marker for invasive bacterial infections in children

BACKGROUND: The aim of this study was to test the hypothesis that elevated lipopolysaccharide binding protein (LBP) serum concentration is a useful marker in the early diagnosis of invasive bacterial infection in children. We measured LBP in serum and cerebrospinal fluid (CSF) of children with proven invasive infection caused by Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis. PATIENTS AND METHODS: Samples were collected from 39 children (aged 2 months to 17 years) with bacterial sepsis (n = 19) or meningitis (n = 20). Bacterial infection was diagnosed when a blood or CSF culture was positive and clinical signs of invasive infection were present. The control group consisted of serum (n = 60) and CSF (n = 19) samples from children with neurologic disease, juvenile idiopathic arthritis or viral infection. In 10 patients with bacterial infection, follow-up samples (24 and 48 hours) were available. LBP values were measured by an immunochemiluminescence analyzer (IMMULITE; DPC Biermann, Bad Nauheim, Germany) and compared with tumor necrosis factor-alpha and interleukin-8 concentrations. RESULTS: The median LBP serum concentrations in patients with bacterial infection were markedly elevated compared with the control groups (45.0 [33.1-55.2] versus 8.3 [6.8-10.1] microg/mL [median and 5-95% confidence interval]; P < 0.0001). Follow-up serum values of LBP were persistently elevated despite adequate antibiotic treatment, whereas tumor necrosis factor-alpha and interleukin-8 concentrations decreased. In contrast, LBP concentrations in the CSF were below the detection limit of 0.5 microg/mL in 67% of patients with bacterial meningitis (median <0.5 microg/mL), whereas tumor necrosis factor-alpha and interleukin-8 levels were highly elevated. CONCLUSION: LBP serum concentration is elevated in serum of children with invasive bacterial infection and could be a promising diagnostic marker.     

Childhood bacterial meningitis in Pondicherry, South India

Objective: To identify causative bacteria from cerebrospinal fluid (CSF) of children with miningits and analyse various clinical and laboratory parameters.Methods: Over a 20 month period, September 1994 to April 1996, one hundred episodes of acute bacterial meningitis in children aged 1 month–12 years were studied in a tertiary urban hospital in South India. Organisms were isolated from the cerebrospinal fluid (CSF) in 35% of cases. Among infants and children, the two major pathogens wereH. influenzae (17%) andS.pneumoniae (12%).Results: The illness at presentation was mild in 13% and severe in 36% of cases. The association of subdural effusion in children with Salmonella Gp B meningitis merits attention. The overall case fatality rate was 25%.S.pneumoniae had a higher case fatality rate than Salmonella Gp B andH.influenzae (50% vs 17% vs 12%). All the three infants below 3 months of age withS.pneumoniae meningitis died. On analysis of selected clinical and laboratory features by discriminant analysis, CSF culture was the significant (P=0.02) variable in relation to outcome. In pneumococcal meningitis, CSF WBC count was a highly significant variable in relation to outcome (Wilk’s Lambda 0.15, F=24.64, P=0.0002).Conclusion: Prevention of infections due toH.influenzae andS.pneumoniae should be given higher priority.